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Duties of Contractors

CDM (GB) Knowledge Base


Contractors are those actually doing the construction work and are most at risk of injury and ill health. Anyone who directly employs, engages construction workers or controls or manages construction work is a contractor for the purposes of these regulations. This includes companies that use their own workforce to do construction work on their own premises. The duties on contractors apply whether the workers are employees or self-employed and to agency workers without distinction.

Regulation 15 of the CDM 2015 regulations places duties on contractors. The HSE Guidance states:

The main duty is to plan, manage and monitor the work under their control. Other duties include:

  1. complying with directions given to them by either the principal designer or principal contractor on sites where there is more than one contractor; and
  2. preparing a construction phase plan on sites where they are the only contractor.

Who is a contractor?

Anyone who directly employs or engages construction workers or manages construction is a contractor. An individual, a sole trader, a self-employed worker, or a business that carries out, manages or controls construction work as part of their business can be a contractor. This also includes companies that use their own workforce to do construction work on their own premises. The duties on contractors apply whether the workers under their control are employees, self-employed or agency workers.

Where contractors are involved in design work, including for temporary works, they also have duties as designers.

Why is a contractor important?

Contractors and the workers under their control are those most at risk of injury and ill-health. They can influence the way in which work is carried out to secure their own health and safety and that of others affected. They have an important role in planning, managing and monitoring the work (in liaison with the principal contractor, where appropriate) to ensure risks are properly controlled. The key to this is the proper coordination of the work, underpinned by good communication and cooperation with others involved.

What must a contractor do?

Contractors have a number of specific duties. They must also comply with the requirements of regulation 8 as they apply to contractors. These include the requirements:

  1. on anyone appointing a designer or contractor (such as the contractor appointing a sub-contractor) to ensure the designer or contractor has the skills, knowledge and experience and, where relevant, organisational capability to carry out the work for which they are being appointed; and
  2. to cooperate with other duty holders.

Making clients aware of their duties

Contractors must not carry out any construction work on a project unless they are satisfied that the client is aware of the duties the client has under CDM2015 (regulation 15(1)). In cases where the contractor is the only one involved, they must liaise directly with the client to establish this. Liaison can be done as part of routine business during early meetings with the client to discuss the project. Contractors should make sure they have a sufficient knowledge of client duties as they affect the project so they can give proper advice. The level of advice will depend on the knowledge and experience of the client and the complexities of the project.

Planning, managing and monitoring construction work


Contractors are required to plan, manage and monitor the construction work under their control so that it is carried out in a way that controls the risks to health and safety (regulation 15(2)). The effort devoted to planning, managing and monitoring should be proportionate to the size and complexity of the project and the nature of risks involved.

On projects involving more than one contractor, this will involve the contractor co-ordinating the planning, management and monitoring of their own work with that of the principal contractor and other contractors, and where appropriate the principal designer. Such coordination could involve regular progress meetings with other duty holders to ensure that the contractor's arrangements for planning, managing and monitoring their own work can feed into, and remain consistent with, the project-wide arrangements. For single contractor projects, the arrangements to plan, manage and monitor the construction phase will normally be simpler.


In planning the work, the contractor must take into account the risks to those who may be affected e.g. members of the public, and those carrying out the construction work. Planning should cover the same considerations as those for the principal, including considering the risks and ensuring the measures needed to protect those affected are in place.

On projects involving more than one contractor, each contractor must plan their own work so that it is consistent with the project-wide arrangements. Contractors should expect help from other duty holders, for example the client who must provide the pre-construction information (Appendix 2 of the CDM2015 guidance provides further help on the provision of pre-construction information).

On single contractor projects, the contractor is responsible for planning the construction phase and for drawing up the construction phase plan before setting up the construction site. The client must provide any relevant pre-construction information they possess and the time and other resources to help the contractor do this. For further guidance see Construction Phase Plan.


The arrangements for managing construction work must take into account the same issues that principal contractors must consider.


The contractor should monitor their work to ensure that the health and safety precautions are appropriate, remain in place and are followed in practice. Effective monitoring by the contractor must address the same issues that principal contractors must consider. This includes using a mix of measures to check performance and taking prompt action when issues arise.

On projects involving more than one contractor, as part of the duty to cooperate with other duty holders, the contractor should provide the principal contractor with any relevant information that stems from their own monitoring so that the principal contractor can monitor the management of health and safety at a project-wide level.

Complying with directions and construction phase plan

For projects involving more than one contractor, the contractor is required to comply with any directions to secure health and safety given to them by the principal designer or principal contractor (regulation 15(3)(a)). They are also required to comply with the parts of the construction phase plan that are relevant to their work (regulation 15(3)(b), including the site rules see (link) for further guidance on the construction phase plan.

Drawing up a construction phase plan

For single contractor projects, the contractor must ensure a construction phase plan is drawn up as soon as practicable before the construction site is set up (regulation 15(5)). Guidance on contractors' duties in relation to the construction phase plan is set out in Appendix 3 of the CDM2015 guidance.

  • Further guidance, including a template for a construction phase plan, is provided for contractors working on small scale, routine and domestic projects on HSE's website -
  • A smartphone "app" providing a template for a construction phase plan is also available from the Construction Industry Training Board website -

Appointing and employing workers

Appointing workers:

When a contractor employs or appoints an individual to work on a construction site, they should make enquiries that the individual:

  1. has the necessary skills, knowledge, training and experience to carry out the work they will be employed to do in a way that secures health and safety for anyone working on the site; or
  2. are in the process of obtaining them.

Reliance should not be placed on an industry certification card or similar being presented to them as evidence that a worker has the necessary qualities. Nationally recognised qualifications (such as NVQs and SVQs) will provide contractors with assurance that the holder has the necessary skills, knowledge, training and experience to carry out a task in such a way. Contractors should recognise that training on its own is not enough. Newly trained individuals need to be supervised and given the opportunity to gain positive experience of working in a range of conditions.

When appointing individuals who may be skilled but who do not have any formal qualifications, contractors may need to assess them in the working environment.

Training workers:

To establish whether training is necessary for any worker, a contractor should:

  1. assess the existing health and safety skills, knowledge, training and experience of their workers;
  2. compare these existing attributes with the range of skills, knowledge, training and experience they will need for the job; and
  3. Identify any shortfall between (a) and (b) above.

The difference between the two will be the 'necessary training'. As a general rule, if the person being assessed demonstrates the required qualities then no further training should be necessary. This assessment should take account of the training required by other health and safety legislation as well as that needed to meet the requirements of CDM 2015.

Assessing training needs should be an on-going process throughout the duration of the project. Further training may be required if:

  1. the risks to which people are exposed alter due to a change in their working tasks;
  2. new technology or equipment is introduced; or
  3. the system of work changes.

Skills can also decline if they are not used regularly. Particular attention should be paid to people who deputise for others on an occasional basis - they may need more frequent further training, than those who do the work regularly.

Contractors should also consider 'softer skills' such as the ability to foresee risk, maintain sensitivity to risk, anticipate mistakes others might make and to communicate clearly, as well as the more technical skills workers require for their work.

Providing supervision:

A contractor who employs workers or manages workers under their control must ensure that appropriate supervision is provided (regulation 15(8)). The level of supervision provided will depend on the risks to health and safety involved, and the skills, knowledge, training and experience of the workers concerned.

Workers will require closer supervision if they are young, inexperienced, or starting a new work activity. In these circumstances, arrangements should be put in place for supervision to continue even when the supervisor is not present. Other factors that should be considered when assessing the level of supervision needed include the level of individuals' safety awareness, education, physical agility, literacy and attitude. Even experienced workers may need an appropriate level of supervision if they do not have some or all of the skills, knowledge, training and experience required for the job and the risks involved.

Supervisors are a vital part of effective management arrangements. Effective supervisors are those who have the skills, knowledge, training, experience and leadership qualities to suit the job in hand. Good communication and people management skills on site are important qualities for supervisors. Where site workers are promoted to a supervisory role, they should be provided with nationally recognised site supervisor training which includes components covering leadership and communication skills.

The role of the supervisor may include team leading, briefing and carrying out toolbox talks. It may also include coaching and encouragement of individual workers and supporting other formal and informal means of engaging with workers. The supervisor has a particularly important part to play as a front line decision maker in emergencies or when workers on-site face immediate risks that may require work to stop.

Providing information and instructions

Contractors should provide their employees and workers under their control, the information and instructions they need to carry out their work without risk to health and safety (regulation 15(9)). This must include:

  1. suitable site induction where this has not been provided by the principal contractor. In such cases, the guidance provided in paragraphs 133-134 of the CDM2015 guidance for principal contractors is relevant to contractors;
  2. the procedures to be followed in the event of serious and imminent danger to health and safety. These should make clear that any worker exposed to any such danger should stop work immediately, report it to the contractor and go to a place of safety. The procedures should:
    • include details of the person to whom such instances should be reported and who has the authority to take whatever prompt action is needed;
    • take account of the relevant requirements which set out provisions relating to emergency procedures, emergency routes and exits and fire detection and fire-fighting.
  3. information on the hazards present on the site that are relevant to their work (e.g. site traffic), the risks associated with those hazards and the control measures put in place (e.g. the arrangements for managing site traffic)

Further guidance is set out in within the CDM2015 guidance.

Preventing unauthorised access to the site

A contractor must not begin work on a construction site unless reasonable steps have been taken to prevent unauthorised access to the site (regulation 15(10)). On projects involving more than one contractor, carrying out this duty must involve the contractors liaising with the principal contractor who is required to ensure reasonable steps are taken in this respect. This can be done via a phone call before the contractor starts work on site or at an early meeting.

For projects involving only one contractor, the contractor must do whatever is proportionate to prevent unauthorised access before starting work on the site. In these circumstances, the guidance provided for principal contractors is also relevant for contractors.

Providing welfare facilities

Contractors are required to provide welfare facilities which meet the minimum requirements set out in Schedule 2 (regulation 15(11)). This duty only extends to the provision of welfare facilities for the contractor's own employees who are working on a construction site or anyone else working under their control. The duty is as far as is reasonably practicable, so contractors should do whatever is proportionate in providing the welfare facilities set out in Schedule 2. Guidance on what is proportionate in providing welfare facilities on construction sites is contained in HSE's Construction Information Sheet - Provision of welfare facilities during construction work (CIS 59). On projects involving more than one contractor, meeting this duty will involve discussing and agreeing with the principal contractor who has a similar duty to provide welfare facilities. For projects involving only one contractor, the contractor themselves must ensure that suitable welfare facilities are available.

When working for domestic clients

A contractor's role when working on a project for a domestic client is no different to the role undertaken for commercial clients. They must still carry out the duties set out in regulations 8 and 15 to the extent necessary given the risks involved in the project. However, the effect of regulation 7 is to transfer the duties of the domestic client to another duty holder, including the contractor in certain circumstances. Appendix 5 of the CDM2015 guidance provides further details on how this will affect what contractors must do on domestic projects. For more information, see Domestic Clients.